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Pinaceae Lindley 1836Common namesPine family, [Chinese].
Taxonomic notesSometimes treated as the sole family of Order Pinales Dumort. 1829. Syn: Abietaceae. Eleven genera and about 210-220 species.Pinaceae are known in the fossil record since the Cretaceous. The family originally included all conifers but is now restricted to a clearly monophyletic group united by characters seen in the mature seed cones: bract-scale complexes consisting of well-developed scales that are free from the subtending bracts for most of their length, two inverted ovules on the adaxial face of each scale, and a (usually obvious) seed wing developed from the cone scale (1). Cone and seed characters further serve to discriminate the four subfamilies, as follows (2, 3): Subfamily Pinoideae. Cones with a distinct umbo from 2(3) season growth, scales with a broad base. Seedwing holding the seed in a pair of claws; no resin vesicles on the seed. Micropylar fluid (in conelets at pollination) present.
Subfamily Piceoideae. Cones without an umbo, scales with a broad base. Seed blackish, loosely held on a cup on the seedwing; no resin vesicles on the seed. Micropylar fluid present.
Subfamily Laricoideae. Cones without an umbo, scales with a broad base. Seeds whitish, firmly fixed to the seedwing; no resin vesicles on the seed. Micropylar fluid absent.
Subfamily Abietoideae. Cones without an umbo, scales with a narrow base. Seeds brown, moderately firmly fixed to the seedwing; resin vesicles present on the seed. Micropylar fluid absent.
DescriptionTree: Trees, occasionally shrubs, evergreen (annually deciduous in Larix and Pseudolarix), resinous and aromatic, monoecious.Bark: Smooth to scaly or furrowed. Branches: Lateral branches well developed and similar to leading (long) shoots, or reduced to well-defined short (spur) shoots (Larix, Pseudolarix, Cedrus) or dwarf shoots (Pinus); twigs terete, sometimes clothed by persistent primary leaves or leaf bases; longest internodes between leaves less than 1 cm; buds conspicuous. Roots: Fibrous to woody, unspecialized, commonly with an ectomycorrhiza. Leaves: Leaves simple, shed singly (whole fascicles shed in Pinus), alternate and spirally arranged but sometimes twisted at the base so as to appear 1- or 2-ranked, or fascicled, linear to needlelike, sessile to short-petiolate; foliage leaves either borne singly (spirally) on long shoots or in tufts (fascicles) on short shoots; juvenile leaves (when present) borne on long shoots; resin canals present. Cotyledons 2-15(-24). Cones: Seed cones maturing in 1 season (2-3 seasons in Pinus) and shed soon after, or long-persistent, sometimes serotinous (not opening upon maturity but much later: some Pinus), compound, axillary, solitary or grouped. Cone scales: Overlapping, free from subtending included or exserted bracts for most of length, spirally arranged, strongly flattened, at maturity relatively thin to strongly thickened and woody (in Pinus), with 2 inverted, adaxial ovules. Pollen cones: Matured and shed annually, solitary or clustered, axillary, ovoid to ellipsoid or cylindric; sporophylls overlapping, bearing 2 abaxial microsporangia (pollen sacs); pollen spheric, 2-winged, less commonly with wings reduced to frill (in Tsuga sect. Tsuga), or not winged (in Larix and Pseudotsuga). Seeds: Two per scale, elongate terminal wing partially decurrent on seed body (wing short or rudimentary in some species of Pinus); aril lacking (1, 4). RangeThe Northern Hemisphere: south to the West Indies, Central America, Japan, China, Indonesia (one species, Pinus merkusii, crosses the equator in Sumatra), the Himalaya, and North Africa. The family is dominant in the vegetation of large regions including (in North America) forests of the boreal and Pacific regions, the western mountains, and the southeastern coastal plain (1). Various species, most commonly Pinus radiata, have been widely introduced for timber production in sub-Saharan Africa, South America, New Zealand and Australia.Big TreePseudotsuga menziesii, with Picea sitchensis a close second.OldestPinus longaeva.DendrochronologyThe majority of all dendrochronological research has involved species of the Pinaceae. Very many studies have involved species of Picea and Pinus, fewer but still a great many studies have involved Abies, Larix, Pseudotsuga and Tsuga, and rather few studies have involved the smaller genera.EthnobotanyMembers of the Pinaceae provide most of the world's softwood timber. They also provide pulpwood, naval stores (e.g., tar, pitch, turpentine, etc.), essential oils, and other forest products. Many species, including most of the genera, are grown as ornamentals and shelter-belt trees and for revegetation. The genera most commonly seen in cultivation are Abies, Cedrus, Larix, Picea, Pinus, Pseudotsuga, and Tsuga, each of these genera being represented by numerous cultivars. Keteleeria and Pseudolarix are mainly botanical garden subjects. Cathaya and Nothotsuga, the most recently described genera (1958, 1988), are apparently not yet in cultivation in North America (1).ObservationsSee the generic and species descriptions.Remarks:Citations(1) John W. Thieret at the Flora of North America web site.(2) M. P. Frankis 1989. Generic inter-relationships in Pinaceae. Notes Roy. Bot. Gard. Edinburgh 45: 527-548. (3) Farjon 1990. (4) Material contributed for this description by M.P. Frankis, 30-Jan-1999. See also:
This page was co-edited with Michael Frankis, Jan-1999. | |
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